raspi{vid,still} --exposure verylong doesn’t work

[towolf]

Switching to MMAL_PARAM_EXPOSUREMODE_NIGHT is very nifty, as can be seen here:

It gives shots with low light much more exposure time, at the cost of fixed fps. You can see it ramps fps down as light fades and then flatlines at 4fps.

First question, why 4fps. Could it go lower?

To see how low I wonder what MMAL_PARAM_EXPOSUREMODE_VERYLONG does.

And why does it not work?

[GeorgViehoever]

-ex verylong seems to freeze the camera. Exposure never ends... if you stop raspistill with ^C, the camera remains active (LED is still illuminated), and camera cannot be used until reboot.

[JamesH65]

Investigation shows this may be a problem with some numbers being sent at a very low level to the camera. But the numbers look OK (we are doing exactly as we would do with other camera types), so have called in Omnivision to give it the once over to see if there is some weird setting I have missed. It's a bit odd.

[JamesH65]

I believe the freeze when using the longer exposure times is now fixed so closing.